In the production processes for semiconductor devices, a polishing process is carried out to subject a surface of a wafer to a planarization. A polishing process can be applied to different materials of surfaces of the wafer multiple times during different stages of fabrication processing of a semiconductor device. In the process of chemical mechanical polishing, the wafer is mounted to a rotating plate, and a surface of the wafer is brought into contact with a pad of a polishing machine. Rotating the rotating plate and the pad of the polishing machine while a slurry is supplied. That is, a slurry flows between the wafer surface and the pad, and polishing of the wafer surface is achieved as a result of the mechanical friction caused by the polishing particles in the slurry and the protrusions at the surface of the pad.